Fix CommonSpaces and MPI

The `CommonGrids` module passes down the context to all the grid it
creates. This is a problem for IntervalTopology, because it can only be
created with Singletons.

This commit fixes this issue and adds test checking that we can create
CommonSpaces with MPI and CUDA

.buildkite/pipeline.yml

@@ -273,6 +273,35 @@ steps:
         agents:
           slurm_gpus: 1
 
+      - label: "Unit: common spaces with CUDA"
+        key: "gpu_common_cuda_spaces"
+        command:
+          - "julia --color=yes --check-bounds=yes --project=.buildkite test/CommonSpaces/unit_common_spaces.jl"
+        env:
+          CLIMACOMMS_DEVICE: "CUDA"
+        agents:
+          slurm_gpus: 1
+
+      - label: "Unit: common spaces with CUDA and MPI"
+        key: "gpu_common_cuda_mpi_spaces"
+        command:
+          - "srun julia --color=yes --check-bounds=yes --project=.buildkite test/CommonSpaces/unit_common_spaces.jl"
+        env:
+          CLIMACOMMS_CONTEXT: "MPI"
+          CLIMACOMMS_DEVICE: "CUDA"
+        agents:
+          slurm_gpus: 1
+          slurm_ntasks: 2
+
+      - label: "Unit: common spaces with MPI"
+        key: "common_cuda_mpi_spaces"
+        command:
+          - "srun julia --color=yes --check-bounds=yes --project=.buildkite test/CommonSpaces/unit_common_spaces.jl"
+        env:
+          CLIMACOMMS_CONTEXT: "MPI"
+        agents:
+          slurm_ntasks: 2
+
       - label: "Unit: distributed cuda spaces"
         key: "gpu_distributed_extruded_cuda_spaces"
         command:

NEWS.md

@@ -2,6 +2,14 @@ ClimaCore.jl Release Notes
 ========================
 
 main
+-------
+
+- Prior to this version, `CommonSpaces` could not be created with
+`ClimaComms.MPICommContext`. This is now fixed with PR
+[2176](https://github.com/CliMA/ClimaCore.jl/pull/2176).
+
+
+v0.14.24
 -------
 
  - A new `Adapt` wrapper was added, `to_device`, which allows users to adapt datalayouts, spaces, fields, and fieldvectors between the cpu and gpu. PR [2159](https://github.com/CliMA/ClimaCore.jl/pull/2159).

src/CommonGrids/CommonGrids.jl

@@ -189,7 +189,10 @@ function ExtrudedCubedSphereGrid(
         horizontal_layout_type,
         enable_bubble,
     )
-    z_topology = Topologies.IntervalTopology(context, z_mesh)
+    z_topology = Topologies.IntervalTopology(
+        ClimaComms.SingletonCommsContext(device),
+        z_mesh,
+    )
     z_grid = Grids.FiniteDifferenceGrid(z_topology)
     return Grids.ExtrudedFiniteDifferenceGrid(
         h_grid,
@@ -307,6 +310,7 @@ function ColumnGrid(
     ),
 ) where {FT}
     @assert ClimaComms.device(context) == device "The given device and context device do not match."
+    @assert context isa ClimaComms.SingletonCommsContext "Columns can only be created on Singleton contextes."
     z_topology = Topologies.IntervalTopology(context, z_mesh)
     return Grids.FiniteDifferenceGrid(z_topology)
 end
@@ -439,7 +443,10 @@ function Box3DGrid(
         horizontal_layout_type,
         enable_bubble,
     )
-    z_topology = Topologies.IntervalTopology(context, z_mesh)
+    z_topology = Topologies.IntervalTopology(
+        ClimaComms.SingletonCommsContext(device),
+        z_mesh,
+    )
     z_grid = Grids.FiniteDifferenceGrid(z_topology)
     return Grids.ExtrudedFiniteDifferenceGrid(
         h_grid,
@@ -542,10 +549,16 @@ function SliceXZGrid(
     @assert horizontal_layout_type <: DataLayouts.AbstractData
     @assert ClimaComms.device(context) == device "The given device and context device do not match."
 
-    h_topology = Topologies.IntervalTopology(context, h_mesh)
+    h_topology = Topologies.IntervalTopology(
+        ClimaComms.SingletonCommsContext(device),
+        h_mesh,
+    )
     h_grid =
         Grids.SpectralElementGrid1D(h_topology, quad; horizontal_layout_type)
-    z_topology = Topologies.IntervalTopology(context, z_mesh)
+    z_topology = Topologies.IntervalTopology(
+        ClimaComms.SingletonCommsContext(device),
+        z_mesh,
+    )
     z_grid = Grids.FiniteDifferenceGrid(z_topology)
     return Grids.ExtrudedFiniteDifferenceGrid(
         h_grid,

test/CommonSpaces/unit_common_spaces.jl

@@ -16,6 +16,9 @@ using ClimaCore:
     DataLayouts
 using Test
 
+# Initialize MPI context
+ClimaComms.init(ClimaComms.context())
+
 @testset "Convenience constructors" begin
     function warp_surface(coord)
         # sin²(x) form ground elevation
@@ -75,14 +78,17 @@ using Test
     @test grid isa Grids.SpectralElementGrid2D
     @test Grids.topology(grid).mesh isa Meshes.EquiangularCubedSphere
 
-    space = ColumnSpace(;
-        z_elem = 10,
-        z_min = 0,
-        z_max = 1,
-        staggering = Grids.CellCenter(),
-    )
-    grid = Spaces.grid(space)
-    @test grid isa Grids.FiniteDifferenceGrid
+    # Column spaces are not supported with MPI
+    if !(ClimaComms.context() isa ClimaComms.MPICommsContext)
+        space = ColumnSpace(;
+            z_elem = 10,
+            z_min = 0,
+            z_max = 1,
+            staggering = Grids.CellCenter(),
+        )
+        grid = Spaces.grid(space)
+        @test grid isa Grids.FiniteDifferenceGrid
+    end
 
     space = Box3DSpace(;
         z_elem = 10,
@@ -104,21 +110,24 @@ using Test
     @test grid.horizontal_grid isa Grids.SpectralElementGrid2D
     @test Grids.topology(grid.horizontal_grid).mesh isa Meshes.RectilinearMesh
 
-    space = SliceXZSpace(;
-        z_elem = 10,
-        x_min = 0,
-        x_max = 1,
-        z_min = 0,
-        z_max = 1,
-        periodic_x = false,
-        n_quad_points = 4,
-        x_elem = 4,
-        staggering = Grids.CellCenter(),
-    )
-    grid = Spaces.grid(space)
-    @test grid isa Grids.ExtrudedFiniteDifferenceGrid
-    @test grid.horizontal_grid isa Grids.SpectralElementGrid1D
-    @test Grids.topology(grid.horizontal_grid).mesh isa Meshes.IntervalMesh
+    # Slices are currently not compatible with GPU
+    if !(ClimaComms.device() isa ClimaComms.CUDADevice)
+        space = SliceXZSpace(;
+            z_elem = 10,
+            x_min = 0,
+            x_max = 1,
+            z_min = 0,
+            z_max = 1,
+            periodic_x = false,
+            n_quad_points = 4,
+            x_elem = 4,
+            staggering = Grids.CellCenter(),
+        )
+        grid = Spaces.grid(space)
+        @test grid isa Grids.ExtrudedFiniteDifferenceGrid
+        @test grid.horizontal_grid isa Grids.SpectralElementGrid1D
+        @test Grids.topology(grid.horizontal_grid).mesh isa Meshes.IntervalMesh
+    end
 
     space = RectangleXYSpace(;
         x_min = 0,